How to Remove the "Popping" Volume Sound on a Mac

Lion Tip: Tweaking the System Volume and Brightness Adjustments
Have you ever wished that your mac didn’t make those popping noises whenever you are adjusting the volume through the keyboard? Or want to adjust the volume or brightness more precisely than the default up and down keys?

Well, here are some little treats for you!

1) The popping lets you know just how loud the volume currently is. But if you want to change your volume but not hear the pop, just hold down the ‘Shift’ key while changing the volume and you will still see the progress bar increasing and decreasing but no popping!!
2) Want to adjust the volume and brightness in smaller Increments? Hold down the Shift+Option/Alt Keys whilst pressing the volume or brightness UP or DOWN keys to see the setting adjusting in a smaller amount!
3) To open Sound or Display Preferences quickly for more audible and video tweaking select Option/Alt+Volume or Brightness Controls
NOTE: Theses shortcuts from 10.6 were removed in 10.7.0 but have now been restored in 10.7.4